The present invention relates generally to windows for use in buildings and other habitable structures, whether static or mobile. More particularly, the present invention relates to supplemental window assemblies installed about prime windows.
While prime windows, those windows generally usable on a stand-alone basis in fixed buildings, mobile homes, travel trailers and other habitations, are sufficient for structural integrity and habitation security, they are often found to be an insufficient thermal barrier. To conserve the energy necessary for heating and/or cooling a building it has, for example, been suggested to employ supplemental windows in addition to the prime windows. Such supplemental windows have included exterior and interior "storm" windows mounted over the prime windows with a "dead air" space therebetween.
Such supplemental windows are structurally and functionally distinct from prime windows. As noted above, prime windows are typically constructed to provide structural integrity and security for the building. Usually being installed during initial construction or overall renovation of the building, prime windows tend to define the spacial constraints of the window opening, rather than be limited by it. In addition, operating mechanisms of prime windows, such as balancing weights, can be mounted within the wall space outside of and adjacent to the window opening. Prime windows also tend to be relatively heavy and bulky. Further, prime windows typically require professional or highly experienced installers. As a result, and especially where window pane tilt features are employed (as with casement or awning windows), prime windows tend to be relatively expensive.
Supplemental windows, however, are primarily intended to protect the prime window and reduce thermal loses therethrough. In many instances, supplemental windows are intended to be installed by the building owner and/or relatively unexperienced workers. As a result, supplemental windows are preferably lightweight, uncomplicated and inexpensive. To avoid detracting from the appearance of either the building in general or the prime window itself and to fit within often tight pre-existing spacial constraints, supplemental windows have tended to have minimal framework, the visible bulk of the window assembly being the window panes.
Various such supplemental windows are known and, in general, those windows are successful in their intended functions. However, supplemental windows have been typically subject to certain shortcomings and, in some circumstances, have not been practical to use at all. For example, exterior storm windows are often constructed from metal, such as aluminum, in order to have sufficient durability and rigidity for mounting on the exterior face of the building. Frames for these windows have tended to be narrow and simple, merely to provide a channel for the window pane motion in a vertical plane, in order to save on overall weight and cost and to minimize visual distraction from the building exterior.
However, such metal frames are relatively poor thermal insulators, channel-to-pane sealing is often relatively poor without complicated frame designs (especially where the pane is even slightly out of square), and glass weight alone can make raising and lowering of the window panes, as for cleaning, difficult for an average user. Also, "weep holes" or passageways from the environment to the dead air space are usually provided to avoid condensation build up between the exterior storm window and the prime window. Thus, an optimal thermal barrier between the windows is not achieved.
In those instances where the prime window has a pane which can be operated to tilt outward from the vertical plane of the building wall, the close fit of the exterior storm window would prevent that operation. In addition to thereby precluding building ventilation when desired, cleaning the exterior of the prime window pane and the interior of the storm window pane is substantially complicated. Constructing the exterior storm window larger to avoid such difficulties, however, typically precludes removal of the storm window panes through the prime window for cleaning or replacement and makes the exterior visual impression of the storm window more pronounced. Such larger storm window assemblies are not even possible where, for example, shutters are closely mounted to the exterior of the prime window. Further, at certain heights and/or window sizes or in situations involving historic buildings or buildings subject to restrictive covenants, exterior storm windows are simply not available for use as a practical matter.
Interior storm windows, on the other hand, can be installed regardless of building height and legal restrictions on exterior building appearance, but suffer other disadvantages. Such windows have generally been mounted within the window opening or, as described in co-pending U.S. patent application Ser. No. 08/023,599, filed on Feb. 26, 1993, now U.S. Pat. No. 5,390,454, on the interior building wall outside of the window opening. In both cases these windows are preferably constructed with frames from plastic material, such as vinyl, to reduce thermal conductivity, weight, and expense. However, particularly in large windows subject to extended periods of direct sunlight, these materials have been found to sag and warp in response to the weight and thermal stresses. This sagging is destructive of the structural and air seal integrity of the window unit and can increase the difficulty of raising or lowering the window panes. Further, in tall windows vinyl material has been found to lack sufficient rigidity to maintain close air seals between the sides of the window pane and the receiving channels. Moreover, in those instances where such windows are installed within the window opening, custom sizing and installation are typically needed for each window opening, especially when retrofitting such storm windows to older buildings.
Like exterior storm windows, interior storm windows often block operation of prime windows having tilting panes, particularly if that storm window is installed within the window opening. In addition, it can be difficult, due to window pane weight, for an average user to raise, lower and/or remove the larger interior storm window panes for cleaning or access to the prime window. Also, even where the most minimal frame for interior storm windows is installed within the window opening, its dimensions are typically sufficient to block otherwise removable prime window panes, even if the storm window pane is small enough to be readily removed from that frame. Further, when the storm window pane is constructed out of square, with some frames the air seal integrity between the window pane and the receiving channels is degraded. In addition, both types of storm windows often employ latching mechanisms which require use of two hands simultaneously to open.
Accordingly, it is an object of the present invention to provide an improved window assembly to supplement a prime window in a building or other habitable structure. Other objects of this invention include providing:
1. a durable, inexpensive storm window that is easy to install to an existing building,
2. an interior storm window that is easy to open, clean and maintain,
3. a storm window with lower thermal conductivity and higher structural rigidity,
4. a window assembly having improved sealing against air flow therethrough, and
5. an interior storm window that does not interfere with operation, cleaning or maintenance of the associated prime window.
These and other objects of the present invention are attained in an interior storm window assembly, mounted to an interior building wall over a window opening containing a prime window therein, having double hung, vertically movable window pane members received within opposing, self-locating vertical channels and pivotally attached to adjustable weight balancing elements within those channels. The frame structure of the window assembly, including the peripheral rail about each window pane member and the vertical channels, is formed from plastic material, such as vinyl, having low thermal conductivity, and a rigid, reinforcing rod, preferably of metal, is inserted within the plastic rail at the bottom of each window pane member. The vertical channels apply pressure inwardly to the peripheral rails to releasably retain the window pane members in vertical orientation as well as urge the peripheral rails laterally into sealing contact with the vertical channels. An interlocking seal arrangement is also provided between the peripheral rails for further securing against air flow when the window assembly is closed. Weather stripping on the peripheral rails is biased into engagement with compressive ribs on the vertical channels, creating a tortuous air flow path therebetween.
The pivotable attachment of said window pane members allows them to be tilted out of the vertical plane of motion within the self-locating vertical channels to facilitate cleaning of both sides of the window panes and/or the prime window panes. The weight balancing elements allow even large, heavy window pane members to be raised and lowered by virtually any user and often with a single hand. The self-locating vertical channels accommodate out of square window pane members without loss of sealing. The rigid, reinforcing rods support the window pane weight to reduce sagging and distortion of the vinyl portions of the window pane members. Each of the vertical channels includes opposing inclined surfaces or ramps to engage the peripheral rails in a snap-fit connection to maintain vertical orientation of the window pane member.
Other objects, advantages and novel features of the present invention will become readily apparent from consideration of the drawings and detailed description below.